Multi-Panel Display Having Board-To-Board Interfaces Between Adjacent Panels

ABSTRACT

An embodiment display panel includes a housing comprising a recess and framing portions, a printed circuit board (PCB), a sealing material, and a plurality of light emitting diodes (LEDs). The PCB is attached to and overhangs the framing portions of the housing. The PCB includes a front side and an opposite back side. The recess overlies the opposite back side of the PCB. The sealing material is disposed between the opposite back side of the PCB and the framing portions of the housing. The plurality of LEDs is disposed at the front side of the PCB. The front side of the PCB forms an entirety of a front surface of the display panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 15/824,544, filed on Nov. 28, 2017, which application isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to displays including aplurality of display panels, and, in particular embodiments, to amulti-panel display having board-to-board interfaces between adjacentpanels.

BACKGROUND

Large displays (e.g., billboards), such as those commonly used foradvertising in cities and along roads, are widely used to displayimages, video, or text. The graphics may be projected on a single panelor extended across multiple panels. Each panel of a multi-panel displaymay have an array of light emitting diodes (LEDs) to generate the visualgraphics. The LED panels may be conventional panels made using discreteLEDs or surface-mounted device (SMD) panels. Most outdoor screens andsome indoor screens are built around discrete LEDs, which are also knownas individually mounted LEDs. A cluster of red, green, and blue diodes,or alternatively, a tri-color diode, is driven together to form afull-color pixel, usually square in shape. These pixels are spacedevenly apart for a given panel. It may be desirable to provide amulti-panel display where pixels are spaced evenly apart across theentire multi-panel display.

SUMMARY

An embodiment display panel includes a printed circuit board (PCB)including a lower portion and an upper portion disposed over andoverhanging the lower portion of the PCB. The display panel furtherincludes a plurality of light emitting diodes (LEDs) disposed at a frontside of the upper portion of the PCB, where the front side of the upperportion of the PCB forms an entirety of a front surface of the displaypanel. The display panel also includes a housing having a recess, wherethe lower portion of the PCB is at least partially disposed within therecess, where framing portions of the housing are laterally adjacent tothe lower portion of the PCB, and where the upper portion of the PCBoverhangs the framing portions of the housing.

An embodiment modular digital display system includes a supportstructure including a plurality of vertical beams and a plurality ofhorizontal beams; and a plurality of digital display panels mounted tothe support structure so as to form an integrated display panel. Theintegrated display panel includes a display surface, where the supportstructure is configured to provide mechanical support to the pluralityof digital display panels. Each of the plurality of digital displaypanels includes a printed circuit board assembly (PCBA) including a backportion and front portion disposed over and overhanging the back portionof the PCBA; a plurality of light emitting diodes (LEDs) disposed at anexterior-facing surface of the front portion of the PCBA, where theexterior-facing surface of the front portion of the PCBA forms anentirety of a front surface of the digital display panel; and a housingincluding a recess, where the back portion of the PCBA is disposedwithin the recess, where framing portions of the housing are laterallyadjacent to the back portion of the PCBA, where the front portion of thePCBA overhangs the framing portions of the housing, and where PCBAs ofimmediately adjacent digital display panels are in physical contact.

A digital display panel includes a printed circuit board (PCB) includinga lower portion and an upper portion disposed over and overhanging thelower portion of the PCB; a plurality of light emitting diodes (LEDs)disposed at a front side of the upper portion of the PCB, where thefront side of the upper portion of the PCB forms an entirety of a frontsurface of the digital display panel; a housing including a recess,where the lower portion of the PCB is at least partially disposed withinthe recess, where framing portions of the housing are laterally adjacentto the lower portion of the PCB, where the upper portion of the PCBoverhangs the framing portions of the housing, and where no portion ofthe housing extends past the upper portion of the PCB in a top-down viewof the digital display panel; and a receiver circuit mounted to abackside of the lower portion of the PCB, where the receiver circuit isdisposed within the recess of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIGS. 1A and 1B respectively illustrate a front-view and a back-view ofa multi-panel display, in accordance with an embodiment;

FIGS. 2A-2D illustrate back-views of panels attached to a frame of amulti-panel display, in accordance with various embodiments;

FIG. 3A illustrates a front view of a panel with illumination elementsarranged in a 16×32 configuration, in accordance with an embodiment;

FIG. 3B illustrates a panel including a printed circuit board assembly,where a power supply and an light emitting diode (LED) receiver circuitof the panel are assembled on the same printed circuit board as theillumination elements of the panel 104, in accordance with anembodiment;

FIG. 4 illustrates a housing that may enclose the printed circuit boardassembly, the LED receiver circuit, and the power supply shown in FIG.3B, in accordance with an embodiment;

FIG. 5 shows a cross-sectional view of a panel 104, including a housingand a printed circuit board assembly disposed within the housing, inaccordance with an embodiment;

FIG. 6 illustrates a first panel stacked next to a second panel to forma portion of a multi-panel display, where each panel has the structureshown in FIG. 5, in accordance with an embodiment;

FIG. 7 shows a cross-sectional view of a panel 104, including a printedcircuit board assembly that extends across an entire front surface ofthe panel, in accordance with an embodiment;

FIG. 8 illustrates a first panel stacked next to a second panel to forma portion of a multi-panel display, where each panel has the structureshown in FIG. 7, in accordance with an embodiment.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

This disclosure provides many applicable inventive concepts that can beembodied in a wide variety of specific contexts. The specificembodiments discussed are merely illustrative of specific ways to makeand use the invention, and do not limit the scope of the invention.

In the following embodiments, exterior displays are used herein forpurposes of example. It is understood that the present disclosure may beapplied to lighting for any type of interior and/or exterior display.

FIGS. 1A and 1B respectively illustrate a front-view and a back-view ofa multi-panel display 100, in accordance with an embodiment. Themulti-panel display 100 (hereinafter referred to as a “display”)includes a display surface 102 formed by a plurality of lighting panels104 a-104 t (hereinafter referred to as “panels 104”) arranged as anarray of panels 104. Each panel 104 of each row of the array of panels104 is electrically connected to an adjacent panel 104 within that row.In the present embodiment, the panels 104 use light emitting diodes(LEDs) for illumination; however, other light sources may be used inother embodiments. The panels 104 typically operate together to form asingle image across the display surface 102, although multiple imagesmay be simultaneously displayed by the display 100. In the presentexample, each of the panels 104 is attached to a frame 106 (e.g., shownin FIG. 1B), which enables each of the panels 104 to be installed orremoved from the display 100 without affecting other panels 104.

In the display 100 of FIGS. 1A and 1B, each panel 104 is aself-contained unit that couples directly to the frame 106. By“directly,” it is understood that another component or components may bepositioned between the panel 104 and the frame 106, but the panel 104 isnot placed inside weather protection cabinetry that is coupled to theframe 106. For example, an alignment plate may be coupled to a panel 104and/or the frame 106 to aid in aligning a panel 104 with other panels104. Further a corner plate could be used. The panel 104 may then becoupled to the frame 106 or the alignment plate and/or corner plate, andeither coupling approach would be “direct” according to the presentdisclosure.

A first panel 104 can be coupled, for power and/or data purposes, with asecond panel 104 that receives power and/or data from a central sourceor a third panel 104. The second panel 104 may also pass through atleast some of the power and/or data to a fourth panel 104. This furtherimproves the modular aspect of the display 100, since a single panel 104can be easily installed in the display 100 by coupling the power anddata connections of the single panel 104 to neighboring panels 104.Similarly, a single panel 104 can be easily disconnected from thedisplay 100 by decoupling the power and data connections of the singlepanel 104 from neighboring panels 104.

The power and data connections for the panels 104 may be configuredusing one or more layouts, such as a ring, mesh, star, bus, tree, line,or fully-connected layout, or a combination thereof. In someembodiments, the panels 104 may be in a single network; in otherembodiments, the panels 104 may be divided into multiple networks. Powerand data may be distributed using identical or different layouts. Forexample, power may be distributed in a line layout, while data may use acombination of line and star layouts.

The frame 106 that supports the panels 104 may be relatively light inweight compared to frames needed to support cabinet-mounted LEDassemblies. In the present example, the frame 106 includes a tophorizontal member 108, a bottom horizontal member 110, a left verticalmember 112, a right vertical member 114, and intermediate verticalmembers 116, as illustrated in FIG. 11B. Power cables and data cables(not shown in FIGS. 1A-1B) for the panels 104 may route around and/orthrough the frame 106.

In one embodiment, the display 100 includes 336 panels 104 to create a14 feet×48 feet display 100. In such an embodiment, the entire display100 could be built to weigh only 5500 pounds. This compares favorably tocommercially available displays of similar size, which generally weighfrom 10,000 to 12,000 pounds. In another embodiment, the display 100includes 320 panels 104 arranged in ten rows and thirty-two columns tocreate an approximately 16 feet×50 feet display 100.

FIGS. 2A-2D illustrate back-views of panels 104 attached to the frame106 of the display 100, in accordance with various embodiments. Asdepicted in FIG. 2A, the panels 104 are stacked next to and/or aboveeach other (e.g., as an array) and are securely attached to the frame106 using an attachment plate 202, which may be a corner plate. Theattachment plate 202 may include holes through which attachment features204 may be disposed. FIG. 2A shows a data receiver box 206 mounted orsecured to frame 106. The data receiver box 206 is configured to providepower, data, and communication to the panels 104. With a shared receiverbox 206, the panels 104 themselves do not need a respective orindividual receiver card, and such a configuration can save cost andweight.

Referring to FIG. 2B, the frame 106 provides mechanical support andelectrical connectivity to each of the panels 104. The frame 106includes a plurality of beams 208 forming the mechanical structure. Theframe 106 of FIG. 2B includes a top bar, a bottom bar, a left bar, and aright bar, which demarcate the outer boundary of the frame 106. Theframe 106 also includes a plurality of vertical bars extending from thetop bar to the bottom bar and disposed between the left bar and theright bar. The top bar, the bottom bar, the left bar and the right barmay be 4″ aluminum bars and the vertical bars may be 2″×4″×½″ aluminumtubes. The top bar, the bottom bar, the left bar and the right bar mayeach be capable of bearing a load of 1.738 lb./ft., and the verticalbars may each be capable of bearing a load of 3.23 lb./ft.

The frame 106 may include support structures for the electrical cables,data cables, electrical power box powering the panels 104. The frame 106does not include any additional enclosures to protect the panels 104,the data cables, or the power cables from the environment. Rather, theframe 106 is exposed to the elements and further exposes the panels 104to the environment. The frame 106 also does not include airconditioning, fans, heating units to maintain the temperature of thepanels 104. Rather, each of the panels 104 is hermetically sealed and isdesigned to be exposed to the outside ambient. Further, in variousembodiments, there are not additional weather protection cabinetry thatare attached to the frame 106 or used for housing the panels 104.Accordingly, in various embodiments, the display 100 is designed to bepassively cooled.

FIGS. 2C and 2D illustrate alternative embodiments of the display 100attached to the frame 106. The embodiment shown in FIG. 2C differs fromembodiment described in FIG. 2A in that the horizontal beams 208A shownin FIG. 2C may be used to support the panels 104. In one embodiment,both horizontal beams 208A and vertical beams 208B may be used tosupport the panels 104. In another embodiment, horizontal beams 208A butnot the vertical beams 208B may be used to support the panels 104,although the vertical beams 208B may be used to reinforce the frame 106rather than directly support the panels 104. The embodiment shown inFIG. 2D shows that the frame 106 may include additional beams 208C,which may be narrower in width than the other beams of the frame 106.One or more of the thinner beams 208C may be placed between the regularsized vertical beams 208B, e.g., to reinforce the frame 106.

FIGS. 3A-3B show various aspects of a panel 104, in accordance with anembodiment. FIG. 3A illustrates a front view of the panel 104 withillumination elements (e.g., LEDs) arranged in a 16×32 configuration, inaccordance with an embodiment. FIG. 3B illustrates an embodiment wherethe panel 104 includes a printed circuit board (PCB) assembly (PCBA),where a power supply and an LED receiver circuit are assembled on thesame PCB as the illumination elements of the panel 104.

Referring to the example of FIG. 3A, the panel 104 includes a PCBA 302that forms at least a portion of the front surface of the panel 104. Thepanel 104 may have a width W (e.g., between 1 foot and 4 feet) and aheight H (e.g., between 0.5 feet to 2 feet), although other dimensionsmay be possible. In some embodiments, a ratio of the height H to thewidth W may be about 0.5. The PCBA 302 in the present embodiment isrectangular in shape, with a top edge 304, a bottom edge 306, a rightedge 308, and a left edge 310.

A PCBA surface 312 includes “pixels” 314 that are formed by one or moreLEDs 316 on or within the PCBA 302. In the present example, each pixel314 includes four LEDs 316 arranged in a pattern (e.g., a square). Forexample, the four LEDs 316 that form a pixel 314 may include a red LED,a green LED, a blue LED, and one other LED (e.g., a white LED). In someembodiments, the one other LED may be a sensor. It is understood thatmore or fewer LEDs 316 may be used to form a single pixel 314, and theuse of four LEDs 316 and their relative positioning as a square is forpurposes of illustration only.

In some embodiments, the LEDs 316 may be of a dual in-line package (DIP)LED type. In DIP LED technology, the DIP LED may only display one colorper device. As a result, a blue diode, a green diode, and a red diodeare typically positioned proximate to each other to form a pixel. DIPdiodes typically have a bullet shape design, are generally soldered to aprinted circuit board, and may generate between 35 and 80 lumens perwatt. Alternatively, in some embodiments, the LEDs 316 may be of asurface-mount device (SMD) LED module type. In an SMD LED module, theLED module is a self-contained surface-mounted LED device that isusually mounted to the PCBA 302. SMD LED's are typically less bulky incomparison with DIP LEDs, generally having a flat design. As SMD LED'shave the Red Green Blue (RGB) capability on a single chip, an adjustmentof the level output from each diode on the chip creates a desired outputcolor. A typical SMD LED can produce between 50 and 100 lumens per watt.Other types of LED technology such as organic LED (OLED), edge emittingLED (ELED), chip on board (COB) and multiple chip on board (MCOB), wheremultiple diodes are positioned on a same chip, can be used in the panel104.

Louvers 318 may be positioned between adjacent rows of pixels 314 toblock or minimize light from directly striking the LEDs 316 from certainangles. For example, the louvers 318 may be configured to extend fromthe PCBA 302 to a particular distance and/or at a particular angleneeded to completely shade each pixel 314 when a light source (e.g., thesun) is at a certain position (e.g., ten degrees off vertical). In thepresent example, the louvers 318 extend across the entire length of thePCBA 302, but it is understood that other louver configurations may beused.

Referring to FIG. 3B, one embodiment of the panel 104 illustrates thatthe panel 104 includes an LED receiver circuit 320, a power supply 322,and the LEDs 316 on or within the PCBA 302. The LED receiver circuit 320is coupled to the LEDs 316 (e.g., by circuitry extending through athickness of the PCBA 302). The power supply 322 provides power to thepanel 104 components, such as the LEDs 316 and the LED receiver circuit320. In addition to the LED receiver circuit 320 and the power supply322 circuitry, the PCBA 302 may have other components 303, for example,a controller that is used to control and adjust specific settings of thepanel 104.

In an embodiment, the LED receiver circuit 320 may be a chip mounted onthe PCBA 302. The LED receiver circuit 320 may be configured to processreceived media and control the operation of the individual LEDs 316. Asan example, the LED receiver circuit 320 may determine the color of theLEDs 316 to be displayed at each location (pixel). In an embodiment, theLED receiver circuit 320 may receive digital packets or analog signalsfrom an external computer or controller. The LED receiver circuit 320may then decode, buffer, or perform other signal processing on thereceived digital packets or analog signals and form a representation ofan image to be displayed by controlling the LEDs 316 accordingly.

Similarly, the LED receiver circuit 320 may determine the brightness ateach pixel 314 location, for example, by controlling the currentsupplied to the LEDs 316. In another embodiment, the brightness of theLED 316 may be controlled by turning the LED 316 on and off viapulse-width-modulation (PWM). In some embodiments, the LED receivercircuit 320 and the power supply 322 are configured with bothcapabilities.

The power supply 322 is typically configured to provide aconstant-current drive to the LEDs 316. In some embodiments, the powersupply 322 is configured to provide a constant Direct Current (DC)voltage to the LEDs. In an embodiment, the power supply 322 may includea power converter for converting Alternating Current (AC) to DC, whichis then supplied to the LEDs 316. In an embodiment, the power supply 322converts a 240V or 120V AC to several volts up to in some cases 24V DC.As an example, the panel 104 may operate at 4.2 V DC, for example,providing 160 Watts to the LEDs 316 of the panel 104. Advantageously,the panel 104 can handle either 240V or 120V AC and is thereforecompatible worldwide.

In another embodiment, the power supply 322 may include a down converterthat down converts the voltage suitable for driving the LEDs 316. As anexample, the down converter may down convert a DC voltage at a firstlevel (e.g., 12V, 24V, or 48V DC) to a DC voltage at a second level(e.g., 4.2V DC) that is lower than the first level. Examples of downconverters (DC-DC converters) include linear regulators and switchedmode converters such as buck converters.

In some embodiments, the output from the power supply 322 is isolatedfrom the input power, also known as isolated converters. Accordingly, invarious embodiments, the power supply 322 may include a transformer. Inanother embodiment, the power supply 322 may include forward,half-bridge, full-bridge, or push-pull topologies.

In some embodiments, the ground of the power supply 322 may be isolatedfrom the LED receiver circuit 320 to reduce noisy ground loops (notshown as it is implemented in the board layout, which is internal to thePCBA 302). In an electrical system, a ground loop occurs when a groundreference at two different locations of a circuit have differentpotentials. A ground loop can cause interference and noise in the videofeed and at the LED receiver circuit 320. In an embodiment, the powersupply 322 may be placed inside a faraday cage to minimize RFinterference with other components. The power supply 322 may alsoinclude a control loop circuit to control output current.

Each panel 104 may have ports and mounting latches to connect toadjacent panels. In these embodiments, data and/or power may be receivedfor only the panel 104 or may be passed on to one or more other panels.Accordingly, the LED receiver circuit 320 and/or power supply 322 may beconfigured to pass data and/or power to other panels in someembodiments. The control signals and external power may also be fed toeach panel in a daisy chain or individually. In some embodiments, thepanel may have a socket for registered jack (RJ)45 standard interface.The RJ45 interface allows the display panel to receive signals digitalpackets or analog signals from an external computer.

FIG. 4 illustrates a housing 400 that may enclose the PCBA 302, the LEDreceiver circuit 320, and the power supply 322 shown in FIG. 3B, inaccordance with an embodiment. As shown in FIG. 4, the housing 400defines a cavity 402 (which may also be referred to as a recess).Structural cross-members 404 and 406 may be used to provide support tothe PCBA 302. The cross-members 404 and 406, as well as other areas ofthe housing 400, may include supports 408 against which the PCBA 302 canrest when placed into position. As shown, the supports 408 may include arelatively narrow tip section that can be inserted into a receiving holein the back of the PCBA 302 and then a wider section against which thePCBA 302 can rest.

The housing 400 may also include multiple extensions 410 (e.g., sleeves)that provide screw holes or locations for captive screws that can beused to couple the PCBA 302 to the housing 400. Other extensions 412 maybe configured to receive pins or other protrusions from the attachmentplate 202, which secures the housing 400 to the frame 106, as describedabove in relation to FIGS. 2A-2D. Some or all of the extensions 412 maybe accessible only from the rear side of the housing 400 (e.g., througha back cover that defines a back surface of the housing 400 and thatencloses the cavity 402) and so are not shown as openings in FIG. 4.

FIG. 5 shows a cross-sectional view of the panel 104, including thehousing 400 and the PCBA 302 disposed within the housing 400, inaccordance with an embodiment. The cross-sectional view shown in FIG. 5is taken along the line A-A′ shown in FIG. 4 and may be conventionalpanel 104 where portions 414 of the housing 400 are laterally adjacentto the PCBA 302 (e.g., to facilitate a seal that protects circuitryhoused within the recess 402 of the housing 400 from the elements). Forexample, as shown in FIG. 5, the PCBA 302 rests against supports 408 ofthe housing 400. The LED receiver circuit 320 and the power supply 322are disposed within the recess 402 of the housing 400, while the LEDs316 are disposed at the front surface of the panel 104. As shown in FIG.5, the housing 400 includes framing portions 414 that are laterallyadjacent to the right edge 308 and the left edge 310 of the PCBA 302. Assuch, for each panel 104 of the display 100, the framing portions 414 ofthe housing 400 may visible at one or more of the edges of the PCBA 302.

The housing 400 is sealed to prevent water from entering the housing400. For example, the housing 400 may be sealed to have an ingressprotection (IP) rating such as IP67, which defines a level of protectionagainst both solid particles and liquids. This ensures that the panel104 can be mounted in inclement weather situations without beingadversely affected. To achieve such sealing, a potting material or asilicone-based material can be formed over the LEDs 316. This materialcan be applied as a liquid, e.g., while heated. The liquid material thenflows into the gaps 416 between the framing portions 414 of the housing400 and the edges of the PCBA 302. The liquid material subsequentlyhardens (e.g., when cooled) and seals the housing 400, preventingingress of solid particles and liquids into the recess 402 of thehousing 400.

As described above, the panels 104 are stacked next to and/or above eachother (e.g., as an array) to form the display 100. FIG. 6 shows anembodiment where first panel 104 a is stacked next to second panel 104 bto form a portion of the display 100. As shown in FIG. 6, framingportions 414 of the housings 400 of adjacent panels 104 a, 104 b mayform a region 600 that is devoid of LEDs 316 and where exteriorsidewalls 414 a of the framing portions 414 of adjacent panels 104 a,104 b are next to each other. This region 600 is also depicted in FIG.1A.

The LEDs 316 of a given panel 104 may have a pitch P. In other words,immediately adjacent LEDs 316 of a given panel 104 may be separated by adistance P, which may range between 5 mm and 8 mm. As an example, whenthe display 100 is used outdoors, the distance P may be between 7 mm and8 mm (e.g., about 7.62 mm). As another example, when the display 100 isused indoors, the distance P may be about 5 mm.

However, due to the region 600, immediately adjacent LEDs 316 ofdifferent panels 104 may be separated by a distance D, which is may bedifferent from (e.g., greater than) the pitch P. As such, the presenceof framing portions 144 between adjacent PCBAs 302 may limit the pixelpitch across the display 100 and cause the display 100 to have regions600 that manifest as seams across the image displayed on display 100. Ingeneral, the housing 400 may be made of thermally conductive plasticthat is relatively light-weight and rigid. Due to expansion andcontraction of the housing 400 and/or inconsistencies in production ofthe housing 400, the framing portions 414 of the housing 400 may bow outor cave in. As such, the exterior sidewalls 414 a of the framingportions 414 of the housing 400 may cease to be flat surfaces.

The difference between the distance D and the pitch P may also beattributed to the inconsistencies in the shape of the framing portions414 of the adjacent housings 400 (e.g., due to expansion and contractionof the housing 400 and/or inconsistencies in production of the housing400). Additionally or alternatively, each panel 104 a, 104 b needs to besecured to (e.g., bolted to) the frame 106, as described above inreference to FIGS. 1A, 1B, and 2A-2D. In such a scenario, thebolt/securement positions on the frame 106 may result in a gap betweenfirst panel 104 a and second panel 140 b such that the framing portions414 of the adjacent housings 400 are not in physical contact with eachother. This may also manifest as seams across the image displayed ondisplay 100.

The above-identified disadvantages of a conventional panel 104 may besolved by a software adjustment that adjusts the brightness of LEDs 316disposed at the edges of the PCBA 302 in an attempt to visually hide theseams across the image displayed on display 100. Other possiblesolutions include manufacturing the housing 400 using materials thathave more controllable tolerances (e.g., aluminum, carbon fibercomposite, titanium alloys). However, such solutions may increaseproduction cost and time and also drive up after-installation debuggingtime.

In view of these disadvantages of a conventional panel, embodimentsdescribed herein include a panel where the PCBA and the housing of eachpanel of the display 100 are adjusted to allow for a PCBA-to-PCBAinterface between adjacent panels (e.g., instead of the scenario in FIG.6 showing a framing portion-to-framing portion interface betweenadjacent panels 104 a, 104 b). Such embodiments allow for a tighter seambetween adjacent panels, while maintaining a seal for each panel thatprotects circuitry of each panel from the elements. Such embodimentsalso maintain the use of plastic in the housing and the use of plasticas the material for the housing. This results in cheaper and lighterpanels, in comparison to solutions that make the housing from materialsthat have more controllable tolerances (e.g., aluminum, carbon fibercomposite, titanium alloys).

FIG. 7 shows a cross-sectional view of a panel 104′ includes a PCBA 302′extends across an entire front surface of the panel 104′, in accordancewith an embodiment. In the example shown in FIG. 7, the housing 400′includes recess 402′ that is configured to enclose the LED receivercircuit 320′ and/or the power supply 322′ of the panel 104′, which areattached to a back-side of the PCBA 302′. The PCBA 302′ includes a frontside, which forms the entire front surface of the panel 104′. In otherwords, the width and length of the panel 104′ is equal to the width andlength of the PCBA 302′. The LEDs 316′ are formed at the front side ofthe PCBA 302′. In some embodiments, such as in the example of FIG. 7,the back-side of the PCBA 302′ rests on supports 408′ that protrude fromcross-member 404′ of the housing 400′. As shown in FIG. 7, the PCBA 302′has a thickness T, which may be between 2 mm and 3 mm. The PCBA 302′includes a first portion 302-1′ (e.g., a lower portion) disposed withinthe housing 400′. The housing 400′ includes framing portions 414′ thatare laterally adjacent to the first portion 302-1′ of the PCBA 302′. ThePCBA 302′ also includes a second portion 302-2′ (e.g., an upper portion)that overhangs the first portion of the PCBA 302′ and the framingportions 414′ of the housing 400′. As such, the PCBA 302′ includes a lip700 (which may be referred to as an overhang) that allows for a way toseal the PCBA 302′ to the housing 400′ and help place the PCBA 302′correctly into the housing 400′. The lip 700 may be formed usingstandard etching processes used to etch conventional printed circuitboards (e.g., including FR4 material). The lip 700 may extend a distanceO from the edge of the first portion 302-2′ of the PCBA 302′, and thedistance O may be between 0.8 mm and 2 mm.

The PCBA 302′ includes left and right edges 308′ and 310′ that aredisposed over the framing portions 414′ of the housing 400′ and thatform outermost edges of the panel 104′. A normal to the edges 308′, 310′of the PCBA 302′ is depicted in FIG. 7 as arrow 702. The framingportions 414′ of the housing 400 have exterior side-walls 414′ that areangled. In particular, a normal to the exterior side-walls 414 a′ of theframing portions 414′ of the housing 400′ is depicted in FIG. 7 as arrow704, and an angle θ subtended between the normal 702 to the edges 308′,310′ of the PCBA 302′ and the normal 704 to the exterior side-walls 414a′ of the framing portions 414′ of the housing 400′ may be greater thanabout 10 degrees (e.g., in the range of about 30-45 degrees).

As shown in FIG. 7, there may be a gap between the lip 700 and theframing portions 414′ of the housing 400′ and a gap between theback-side of the PCBA 302′ and the cross-member 404′. These gaps mayneed to be sealed to protect circuitry housed within the recess 402′ ofthe housing 400′ from the elements. In some embodiments, a pottingmaterial or a silicone-based material can be applied as a viscous liquid(e.g., while heated) on the back-side and/or the lip 700 of the PCBA302′, prior to mounting the PCBA 302′ into the housing 400′. The PCBA302′ is subsequently flipped over and inserted into the housing 400′ toform the structure shown in FIG. 7, but where the potting material orsilicone-based material is disposed in the gap between the lip 700 andthe framing portions 414′ of the housing 400′ and in the gap between theback-side of the PCBA 302′ and the cross-member 404′, thereby sealingthe PCBA 302′ and protecting circuitry housed within the recess 402′ ofthe housing 400′ from the elements.

FIG. 8 shows an embodiment where first panel 104 a′ is stacked next tosecond panel 104 b′ to form a portion of the display 100. Each of thepanels 104 a′ and 104 b′ has the structure of the panel 104′ shown inFIG. 7. As shown in FIG. 8, by having each panel of the display 100 tohave the structure of the panel 104′ shown in FIG. 7, a PCBA-to-PCBAinterface 800 is formed between adjacent panels (e.g., in contrast tothe scenario in FIG. 6 where a housing-to-housing interface is formedbetween adjacent panels 104 a, 104 b). Furthermore, an effect of theangled exterior side-walls 414 a′ of the framing portions 414′ of thehousing 400′ is to decrease or eliminate the effect of expansion andcontraction of the housing 400′ and/or inconsistencies in production ofthe housing 400′. For example, even if there are differences in theshapes or flatness between the framing portions 414′ of adjacenthousings 400′, the gap G between the angled exterior side-walls 414 a′of the framing portions 414′ of the adjacent housings 400′ prevents suchinconsistencies from affecting the distance D between immediatelyadjacent LEDs 316′ of the different panels 104 a′ and 104 b′. Inaddition, as depicted in FIGS. 7 and 8, by positioning the outermostLEDs as close as possible to the edges 308′ and 310′ of the PCBA 302′,the distance D between immediately adjacent LEDs 316′ of the differentpanels 104 a′ and 104 b′ can approach the pitch P, thus allowing forconsistent LED pitch across the entire display 100, which in turn leadsto reduction or elimination of seams across the image displayed ondisplay 100.

It is noted that tolerances achievable by PCBAs 302′ are tighter thantolerances achievable by the housing 400′ (which may be made ofplastic). As such, even if abutting surfaces of the PCBAs 302′ at thePCBA-to-PCBA interface 800 exhibit inconsistencies in shape, suchinconsistencies are smaller in comparison to inconsistencies in thehousing 400′ and the effect of the inconsistencies between abuttingsurfaces of the PCBAs 302′ at the PCBA-to-PCBA interface 800 on thedistance D is minimal.

In summary, embodiments described herein include a panel where the PCBAand the housing of each panel of the display 100 are adjusted to allowfor a PCBA-to-PCBA interface between adjacent panels (e.g., instead ofthe scenario in FIG. 6 showing a framing portion-to-framing portioninterface between adjacent panels 104 a, 104 b). Such embodiments allowfor a tighter seam between adjacent panels, while maintaining a seal foreach panel that protects circuitry of each panel from the elements. Suchembodiments also maintain the use of plastic in the housing and the useof plastic as the material for the housing. This results in cheaper andlighter panels, in comparison to solutions that make the housing frommaterials that have more controllable tolerances (e.g., aluminum, carbonfiber composite, titanium alloys).

An embodiment display panel includes a printed circuit board (PCB)including a lower portion and an upper portion disposed over andoverhanging the lower portion of the PCB. The display panel furtherincludes a plurality of light emitting diodes (LEDs) disposed at a frontside of the upper portion of the PCB, where the front side of the upperportion of the PCB forms an entirety of a front surface of the displaypanel. The display panel also includes a housing having a recess, wherethe lower portion of the PCB is at least partially disposed within therecess, where framing portions of the housing are laterally adjacent tothe lower portion of the PCB, and where the upper portion of the PCBoverhangs the framing portions of the housing.

An embodiment modular digital display system includes a supportstructure including a plurality of vertical beams and a plurality ofhorizontal beams; and a plurality of digital display panels mounted tothe support structure so as to form an integrated display panel. Theintegrated display panel includes a display surface, where the supportstructure is configured to provide mechanical support to the pluralityof digital display panels. Each of the plurality of digital displaypanels includes a printed circuit board assembly (PCBA) including a backportion and front portion disposed over and overhanging the back portionof the PCBA; a plurality of light emitting diodes (LEDs) disposed at anexterior-facing surface of the front portion of the PCBA, where theexterior-facing surface of the front portion of the PCBA forms anentirety of a front surface of the digital display panel; and a housingincluding a recess, where the back portion of the PCBA is disposedwithin the recess, where framing portions of the housing are laterallyadjacent to the back portion of the PCBA, where the front portion of thePCBA overhangs the framing portions of the housing, and where PCBAs ofimmediately adjacent digital display panels are in physical contact.

An embodiment digital display panel includes a printed circuit board(PCB) including a lower portion and an upper portion disposed over andoverhanging the lower portion of the PCB; a plurality of light emittingdiodes (LEDs) disposed at a front side of the upper portion of the PCB,where the front side of the upper portion of the PCB forms an entiretyof a front surface of the digital display panel; a housing including arecess, where the lower portion of the PCB is at least partiallydisposed within the recess, where framing portions of the housing arelaterally adjacent to the lower portion of the PCB, where the upperportion of the PCB overhangs the framing portions of the housing, andwhere no portion of the housing extends past the upper portion of thePCB in a top-down view of the digital display panel; and a receivercircuit mounted to a backside of the lower portion of the PCB, where thereceiver circuit is disposed within the recess of the housing.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments, as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is therefore intended that the appended claims encompassany such modifications or embodiments.

What is claimed is:
 1. A display panel, comprising: a housing comprisinga recess and framing portions, the framing portions comprising exteriorsidewalls; a printed circuit board (PCB) attached to and overhanging theexterior sidewalls of the framing portions of the housing, the PCBcomprising a front side and an opposite back side, wherein the recessoverlies the opposite back side of the PCB; a sealing material disposedbetween the opposite back side of the PCB and the framing portions ofthe housing, wherein the exterior sidewalls are attached to the oppositeback side of the PCB using the sealing material; and a plurality oflight emitting diodes (LEDs) disposed at the front side of the PCB,wherein the front side of the PCB forms an entirety of a front surfaceof the display panel.
 2. The display panel of claim 1, wherein thehousing comprises a plastic material.
 3. The display panel of claim 1,wherein the sealing material in combination with the housing seals theopposite back side of the PCB against inclement environmentalconditions.
 4. The display panel of claim 1, wherein the sealingmaterial comprises a silicone-based material.
 5. The display panel ofclaim 1, further comprising a receiver circuit mounted to the oppositeback side of the PCB, wherein the receiver circuit is disposed withinthe recess of the housing.
 6. The display panel of claim 1, furthercomprising a power supply circuit mounted to the opposite back side ofthe PCB, wherein the power supply circuit is disposed within the recessof the housing.
 7. The display panel of claim 1, wherein the housing isattached to the opposite back side of the PCB using screws.
 8. Thedisplay panel of claim 1, wherein the PCB further comprises a lowerportion and an upper portion disposed over and overhanging the lowerportion, and wherein the overhang of the upper portion of the PCBextends about 1 mm from an edge of the lower portion of the PCB.
 9. Thedisplay panel of claim 1, wherein an angle subtended between a normal toa sidewall of the PCB and a normal to a corresponding one of theexterior sidewalls is greater than 10 degrees.
 10. A modular digitaldisplay system, comprising: a support structure comprising a pluralityof vertical beams and a plurality of horizontal beams; and a pluralityof digital display panels mounted to the support structure so as to forman integrated display panel, the integrated display panel comprising adisplay surface, wherein the support structure is configured to providemechanical support to the plurality of digital display panels, whereineach of the plurality of digital display panels comprises: a housingcomprising a recess and framing portions; a printed circuit boardassembly (PCBA) attached to and overhanging the framing portions of thehousing, the PCBA comprising an exterior-facing front surface and anopposite back surface, wherein the recess overlies the opposite backsurface of the PCBA, and wherein PCBAs of immediately adjacent digitaldisplay panels are in physical contact; a sealing material disposedbetween the opposite back surface of the PCBA and the framing portionsof the housing; and a plurality of light emitting diodes (LEDs) disposedat the exterior-facing front surface of the PCBA, the plurality of LEDsand the exterior-facing front surface of the PCBA being part of thedisplay surface of the modular digital display system, wherein theexterior-facing front surface of the PCBA forms an entirety of a frontsurface of the digital display panel.
 11. The modular digital displaysystem of claim 10, wherein the PCBA of each of the plurality of digitaldisplay panels comprises an FR4 material.
 12. The modular digitaldisplay system of claim 10, wherein the housing comprises a plasticmaterial.
 13. The modular digital display system of claim 10, wherein athickness of the PCBA is between 2 mm and 3 mm.
 14. The modular digitaldisplay system of claim 10, wherein the sealing material in combinationwith the housing seals the opposite back surface of the PCBA againstinclement environmental conditions.
 15. The modular digital displaysystem of claim 10, wherein the sealing material comprises asilicone-based material.
 16. The modular digital display system of claim10, wherein a distance between immediately adjacent LEDs of immediatelyadjacent digital display panels is equal to a distance betweenimmediately adjacent LEDs of a given digital display panel.
 17. Adigital display panel, comprising: a housing comprising a recess andframing portions; a printed circuit board (PCB) attached to andoverhanging the framing portions of the housing, the PCB comprising afront side and an opposite back side, wherein the recess overlies theopposite back side of the PCB; a plurality of light emitting diodes(LEDs) disposed at the front side of the PCB, wherein the front side ofthe PCB forms an entirety of a front surface of the digital displaypanel; a receiver circuit mounted to the opposite back side of the PCB,wherein the receiver circuit is disposed within the recess of thehousing; and a power supply circuit mounted to the opposite back side ofthe PCB, wherein the power supply circuit is disposed within the recessof the housing.
 18. The digital display panel of claim 17, wherein theframing portions of the housing comprise an exterior sidewall directedaway from the opposite back side of the PCB, and wherein an anglesubtended between a normal to a sidewall of the PCB and a normal to theexterior sidewall of the framing portions of the housing is greater than10 degrees.
 19. The digital display panel of claim 17, furthercomprising a silicone-based sealant disposed in a gap between the PCBand framing portions of the housing.
 20. The digital display panel ofclaim 19, wherein the silicone-based sealant in combination with thehousing seals the opposite back side of the PCB against inclementenvironmental conditions.